Isolated unilateral absence of the right proximal pulmonary artery diagnosed in a neonate: A case report and review of the literature.

Isolated unilateral absence of the proximal pulmonary artery is a rare, vascular anomaly that is difficult to diagnose and treat in a timely manner because its symptoms are often not evident in the neonatal period. Failure to treat this condition in its early stages may lead to catastrophic complications later in life. Perinatal fetal echocardiography may be helpful in enabling early intervention by alerting the physician to this anomaly in the neonatal period. We herein report two cases that were diagnosed in the neonatal period; the first case was initially suspected on the basis of fetal echocardiographic findings, while the second case was incidentally diagnosed after the patient was admitted for pneumothorax. Prostaglandin E1 was ineffective in both cases. Staged surgery, initially in the neonatal period and later after the patient's condition stabilized, led to a favorable outcome. The present report also contains a review of seven, previous studies of cases which were diagnosed and treated with prostaglandin E1 during the neonatal period. Learning objective: Fetal echocardiography enables isolated unilateral absence of the right proximal pulmonary artery to be diagnosed in the neonatal period, thereby allowing timely intervention. Initial prostaglandin E1 administration tends to be ineffective, and urgent intervention is usually required. Staged surgery may be a reasonable option for optimizing vascular and alveolar growth.